Like a majority — although not all — commentators, I think that Reinhardt’s narrow opinion striking down Prop 8 was probably represented the right way to proceed:
Still, Reinhardt’s decision to go for a solid base hit rather than a home run represents a sound instinct. Kennedy is much more likely to uphold the ninth circuit if he believes such a ruling to be consistent with his own precedents. Forced to choose between a broad, immediate national right to same-sex marriage and upholding Proposition 8, Kennedy is quite likely to choose the latter. Creating a Bowers-like bad precedent would be a disaster, making it much more difficult to successfully litigate in the future – and also, possibly, allowing states to impose more disabilities on same-sex partnerships.
A ruling that immediately gave California’s 37 million residents the right to same-sex marriage and creates a precedent that would likely expand that right to many other, if not all states in the future would still be a major victory. We have to hope that Judge Reinhardt has read Justice Kennedy correctly.
Much more about the costs and benefits of the approach at the link. See also Lithwick.